Precision ram structure for drop hammers



June 18, 1968 M. K. NYE

PRECISION RAM STRUCTURE FOR DROP HAMMERS 2 Sheets-Sheet 1 Filed Feb. 8, 1966 INVENTOR.

MAXIM/L MN ,6. NYE,

June 18, 1968 M. K. NYE 3,388,583

PRECISION RAM STRUCTURE FOR DROP HAMMERS Filed Feb. 8, 1966 2 Sheets-Sheet FIG. 2.

INVENTOR.

MAY/MIL MN A: NYE,

United States Patent 3,388,583 PRECISIGN RAM STRUCTURE FOR DROP HAMMERS Maximilian K. Nye, Fornhell, Pa. (Box 224, Ellwood City, Pa. 11607) Filed Feb. 8, 1966, Ser. No. 525,939 Claims. (Cl. 72-456) ABSTRACT OF THE DISCLOSURE in the side arms, nesting with the side edges of the ram,

theadjustments thereof providing substantially snug engagement of the ram with the side blocks at the bottom end of the stroke of the ram, with maximum clearance when the ram is elevated to its uppermost position. The V-shaped guide grooves are provided with additional inner vent grooves at their apex portions.

This invention relates to ram structures for drop hammers, and more particularly to a new and improved drop hammer assembly providing an improved action for the ram of the assembly with accompanying reduction in wear.

A main object of the invention is to provide a novel and improved drop hammer assembly including improved action of the ram of the assembly, the assembly being simple in construction, being accurately and easily adjustable to provide optimum guiding action, and being arranged so that the ram is substantially completely and efliciently supported at the bottom end of its operating stroke.

A further object of the invention is to provide an improved drop hammer assembly including improved ramsupporting means, the supporting means being inexpensive in construction, being easy to adjust, providing effective guiding action for the ram over its full stroke, providing maximum support and precise alignment of the ram particularly at the lower end of its stroke, and minimizing wear on the cooperating guiding surfaces of the ram and its associated supporting frame.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

FIGURE 1 is a front elevational view of a drop hammer constructed in accordance with the present invention, shown with its ram in an elevated position substantially at the top end of its operating stroke.

FIGURE 2 is an elevational view, partly in vertical cross-section, of the structure shown in FIGURE 1 with the ram substantially at the lowermost end of its stroke, namely, at the position wherein the movable die carried by the ram is in impact position in relation to the stationary bottom die carried by the base portion of the drop hammer assembly.

FIGURE 3 is an enlarged fragmentary horizontal cross-sectional view taken substantially on the line 33 of FIGURE 1.

FIGURE 4 is a vertical cross-sectional view taken substantially on the line 4-4 of FIGURE 3.

FIGURE 5 is an enlarged fragmentary horizontal cross-sectional view taken substantially on the line 5-5 of FIGURE 2.

Referring to the drawings, 11 generally designates a drop hammer assembly constructed in accordance with the present invention. The assembly 11 comprises a frame consisting of a horizontal base portion 12 having an upstanding central block element 13 on which is secured the upwardly-facing stationary bottom die 14 of the assembly. Die 14 is secured on block 13 in a conventional manner.

Designated at 15, 15 are upstanding side arms which are rigidly-secured to the opposite end portions of the base member 12, said side arms rising substantially perpendicularly to said base member and defining a space therebetween for a reciprocating ram 16 secured to the lower end of a piston rod 17. The piston rod 17 is located substantially midway between and substantially parallel to the side arms 15, 15. Secured to the bottom of the ram opposite the bottom die 14 is the downwardly-facing top die 18 which cooperates with bottom die 14 in a conventional manner to provide a die casting when the ram 16 descends toward a mass of malleable material disposed on the bottom die 14.

The ram 16 is provided with symmetrically downwardly-convergent opposite side edges 19', 19, the angle of inclination of the side edges with the vertical being relatively small, for example, being less than one degree, and preferably having a value providing one-sixteenth of aninch inward clearance for a height of approximately four feet. The side edges 19, 19 of the ram 16 are formed with a plurality of substantially vertically-extending guide grooves 21 which are approximately V-shaped, as shown in FIGURE 3, the grooves including straight inner end groove portions 22 to insure clearance at the apex portions of the grooves for a reason presently to be described.

Respective downwardly-convergent guide members 23, 23 are provided in the side arms 15, 15 at the lower portions of the side arms adjacent the bottom die 14, as shown in FIGURE 1. As shown in FIGURES 3 and 4, the guide members 23 are provided with V-shaped ribs or serrations 25 which are slidably-interengageable with the ribs or serrations defined between the V-shaped grooves 21 in the side edges of ram 16, the serrations 25 being likewise provided with rectangular additional inner clearance grooves 26 located between adjacent serrations 25. The serrations 25 are adapted to slidably-interfit with the serrations defined in the side edges of the ram 16 with minimum clearance at the lowermost end of the stroke of the ram 16 and with increased clearance as the ram 16 rises from this lowermost position. The auxiliary inner grooves 22 and 26 provide air-vent passages to allow air to be exhausted from the spaces between the interengaging serrations as the ram descends to its lowermost position and to allow air to re-enter the space between the serrations when the ram is subsequently lifted, thus allowing true sliding contact between the surfaces of the interengaging serrations at the lower end portion of the stroke of the ram and to allow free disengagement of the serrated regions when the ram is elevated.

As shown in FIGURE 3, the serrations 25 have a small amount of clearance relative to the grooves 21 when the ram is in its elevated position, whereas, said serrations 25 closely interengage with and are substantially snuglyreceived in the grooves 21 when the ram 16 is in its lowermost position, illustrated in FIGURES 2 and 5. Thus, in the lowermost position of the ram it is substantially positively supported so that it is accurately aligned with the vertical center line of the bottom die 14 insuring accurate cooperation between the top die 18 and said bottom die 14. Thus, due to the snug intercngagement of the serrations 25 with the grooves 21 in the opposite side edges of the ram 16 at the lower end portion of the stroke of the ram, accurate registry of the cooperating dies 14 and 18 is assured. At the same time, since the serrations 25 are required to be in actual physical contact with the guide grooves 21 only at the lower end portion of the stroke of ram 16, minimum wear occurs on the surfaces of the guide grooves 21.

The side arms 15, 15 are formed with respective inwardly-facing recesses 27, 27 which have horizontal top and bottom walls 28 and 29 and which have inwardlyconvergent inner wall portions 30 and 31. The wall portions 36 and 31 converge toward horizontal guide bores 32 formed in the side arms 15 and leading to rectangular inner recesses 33. The guide members 23 are shaped to be substantially slidably-received in the recesses 27 and are formed with horizontal shaft portions 34 slidably-engaged in the horizontal bores 32. Horizontal guide bolts 35 are threadedly-engaged in the shaft members 34 and extend slidably through bores 37 horizontally-connecting recesses 33 with the exterior of the side arms, the bores 37 being axially-aligned with the bores 32. Coil springs 38 surround the external portions of the bolts 35, hearing betwee nthe bolt heads and bearing washers 39 surrounding the bolts and bearing against abutment bosses 40 formed on the outside portions of the side arms 15 around the bores 37. The coiled springs 38 exert biasing forces on the guide members 23, urging said guide members outwardly relative to the space between the side arms. The top and bottom portions of the guides are thus urged into abutment with stop screws 42 and 43 horizontally-threaded through the side arms 15 and adjusted to limit the positions of the guide members 23 to those wherein the serrations 25 will be substantially snugly received in the guide grooves 21 at the lowermost end of the stroke of ram 16, as shown in FIGURES 2 and 5.

Thus, the guide members 23 are downwardly-convergent in the same manner as the side edges 19, 19 of the ram 16 so that the ribs 25 are at all times parallel to the guide grooves 21. By adjustment of the top and bottom stop screws 42, 43 associated with each guide member 23, the guide members may be accurately positioned to provide the desired substantially snug interengagement of the serrations 25 with the guide grooves 21 at the lowermost end of the stroke of ram 16.

Lock nuts 45 are provided on the adjustable stop screws 42, 43, said lock nuts being tightened against abutment bosses 46 integrally-formed in the outside wall surfaces of the side arms 15, 15 surrounding the stop screws.

As will be readily apparent, by the structure abovedescribed, namely, by making the side edges of the ram 16 downwardly-convergent and by making the cooperating guide members 23, 23 similarly downwardly-convergent, wearing contact between the side edges of the 1 ram and the guide members is minimized, since actual snug interengagement of serrations 25 with uide grooves 21 only occurs at the lowermost end of the stroke of the ram. At the same time, the ram is adequately braced and supported at this lowermost portion of the stroke so that correct registration of the cooperating dies 14 and 18 is assured and so that the ram is accurately centered at the time working impact occurs.

The ram above-described may be used in any mechanical hammer which has adjustable guides, and wherein the hammer operates either vertically, as above-described, or horizontally. Thus, the hammer may be of a type having vertical side frame elements for holding the guides, as above-described, or, alternatively, the hammer may be of a type having horizontal frame elements for holding horizontal guides, in the type of machine wherein the ram operates horizontally.

While a specific embodiment of an improved drop hammer assembly has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

4 What is claimed is: 1. In a drop hammer assembly, a frame comprising a support, a stationary die mounted on said support, a

pair of arms on spaced portions of said support defining a space therebetween, a reciprocating ram-supporting. piston rod located between and substantially parallel to bers on said arms slidably engaged with the convergent side edges of the ram, said piston rod having an operating stroke wherein the second die is closely adjacent the stationary die at the end of said operating stroke, the convergency of the guide members and the side edges of the ram being such that the ram is substantially snugly received in the guide members when the piston rod is at said end of its operating stroke and such that the ram has a relatively small amount of clearance with respect to said guide members when the piston rod is in a retraeted position relative to said end of its operating stroke.

2. The drop hammer assembly of claim 1, and wherein said arms are formed with respective recesses receiving said guide members.

3. The drop hammer assembly of claim 2, and means to adjust-ably secure said guide members in said recesses.

4. The drop hammer assembly of claim 2, and respective shaft elements on said guide members, said side arms being formed with guide bores slidably receiving said shaft elements, spring means urging the guide members outwardly along the axis of said bores, and adjustable stop means limiting the outward movement of the guide members.

5. The drop hammer assembly of claim 4, wherein said stop means comprises respective pairs of stop screws threadedly engaged in the arms on opposite sides of said guide bores and abutting portions of the guide members.

6. The drop hammer assembly of claim 5, wherein the guide members and the opposite side edges of the ram are formed with slidably interengaging serrations.

7. The drop hammer assembly of claim 1, and wherein the guide members are located at end portions of the arms and are snugly engaged by the side edges of the ram at the end of the stroke thereof.

8. The drop hammer assembly of claim 7, and wherein the angle of inclination of the side edges of the ram with the axis of the piston rod is less than one degree.

9. The drop hammer assembly of claim 8, and wherein said guide members are provided with supporting shafts and said arms are formed with bores slidably receiving said supporting shafts.

10. The drop hammer assembly of claim 9, and adjustable stop means on the arms limiting outward adjustment of the guide members.

References Cited UNITED STATES PATENTS 1,382,571 6/1921 Termune 72-456 1,398,610 11/1921 Tibbels 72-456 1,404,150 1/ 1922 Smith 72-456 1,670,493 5/1928 Clark 72-456 2,453,875 11/1948 Termune -214 2,589,402 3/ 1952 Kropp 72-456 FOREIGN PATENTS 641,586 8/ 1950 Great Britain.

CHARLES W. LANHAM, Primary Examiner.

G. P. CROSBY, Assistant Examiner. 

